1. A. A. Bennett, W. E. Milne and H. Bateman,Numerical Integration of Differential Equations, Dover, New York (1956).
2. E. Bierstone and T. Bloom (to appear).
3. S. Bromberg. Thesis, Centro de Investigaciony de Estudio Avanzados, Instituto Politecnico Nacional, Mexico.
4. C. DeBoor,Polynomial Interpolation, Proc. Int. Cong. Helsinki (1978).
5. P. J. Davis,Interpolation and Approximation, Blaisdell, New York (1963).